Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
接近 2 年 前同步成功

通知 170
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 09 6月, 2009 1 次提交
  3. 08 6月, 2009 2 次提交
  5. 04 6月, 2009 3 次提交
    • J
      rfkill: document /dev/rfkill · f71fea23
      由 Johannes Berg 提交于 
      Add some blurb about /dev/rfkill to the documentation and
fix the "transmiter" spelling error.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      f71fea23
    • J
      rfkill: create useful userspace interface · c64fb016
      由 Johannes Berg 提交于 
      The new code added by this patch will make rfkill create
a misc character device /dev/rfkill that userspace can use
to control rfkill soft blocks and get status of devices as
well as events when the status changes.

Using it is very simple -- when you open it you can read
a number of times to get the initial state, and every
further read blocks (you can poll) on getting the next
event from the kernel. The same structure you read is
also used when writing to it to change the soft block of
a given device, all devices of a given type, or all
devices.

This also makes CONFIG_RFKILL_INPUT selectable again in
order to be able to test without it present since its
functionality can now be replaced by userspace entirely
and distros and users may not want the input part of
rfkill interfering with their userspace code. We will
also write a userspace daemon to handle all that and
consequently add the input code to the feature removal
schedule.

In order to have rfkilld support both kernels with and
without CONFIG_RFKILL_INPUT (or new kernels after its
eventual removal) we also add an ioctl (that only exists
if rfkill-input is present) to disable rfkill-input.
It is not very efficient, but at least gives the correct
behaviour in all cases.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      c64fb016
    • J
      rfkill: rewrite · 19d337df
      由 Johannes Berg 提交于 
      This patch completely rewrites the rfkill core to address
the following deficiencies:

 * all rfkill drivers need to implement polling where necessary
   rather than having one central implementation

 * updating the rfkill state cannot be done from arbitrary
   contexts, forcing drivers to use schedule_work and requiring
   lots of code

 * rfkill drivers need to keep track of soft/hard blocked
   internally -- the core should do this

 * the rfkill API has many unexpected quirks, for example being
   asymmetric wrt. alloc/free and register/unregister

 * rfkill can call back into a driver from within a function the
   driver called -- this is prone to deadlocks and generally
   should be avoided

 * rfkill-input pointlessly is a separate module

 * drivers need to #ifdef rfkill functions (unless they want to
   depend on or select RFKILL) -- rfkill should provide inlines
   that do nothing if it isn't compiled in

 * the rfkill structure is not opaque -- drivers need to initialise
   it correctly (lots of sanity checking code required) -- instead
   force drivers to pass the right variables to rfkill_alloc()

 * the documentation is hard to read because it always assumes the
   reader is completely clueless and contains way TOO MANY CAPS

 * the rfkill code needlessly uses a lot of locks and atomic
   operations in locked sections

 * fix LED trigger to actually change the LED when the radio state
   changes -- this wasn't done before
Tested-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      19d337df
  7. 01 6月, 2009 2 次提交
  9. 21 5月, 2009 1 次提交
  11. 19 5月, 2009 2 次提交
  13. 18 5月, 2009 3 次提交
  15. 15 5月, 2009 2 次提交
  17. 09 5月, 2009 1 次提交
  19. 07 5月, 2009 2 次提交
  21. 05 5月, 2009 1 次提交
    • I
      tcp: extend ECN sysctl to allow server-side only ECN · 255cac91
      由 Ilpo Järvinen 提交于 
      This should be very safe compared with full enabled, so I see
no reason why it shouldn't be done right away. As ECN can only
be negotiated if the SYN sending party is also supporting it,
somebody in the loop probably knows what he/she is doing. If
SYN does not ask for ECN, the server side SYN-ACK is identical
to what it is without ECN. Thus it's quite safe.

The chosen value is safe w.r.t to existing configs which
choose to currently set manually either 0 or 1 but
silently upgrades those who have not explicitly requested
ECN off.

Whether to just enable both sides comes up time to time but
unless that gets done now we can at least make the servers
aware of ECN already. As there are some known problems to occur
if ECN is enabled, it's currently questionable whether there's
any real gain from enabling clients as servers mostly won't
support it anyway (so we'd hit just the negative sides). After
enabling the servers and getting that deployed, the client end
enable really has some potential gain too.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      255cac91
  23. 03 5月, 2009 3 次提交
    • A
      mm: prevent divide error for small values of vm_dirty_bytes · 9e4a5bda
      由 Andrea Righi 提交于 
      Avoid setting less than two pages for vm_dirty_bytes: this is necessary to
avoid potential division by 0 (like the following) in get_dirty_limits().

[   49.951610] divide error: 0000 [#1] PREEMPT SMP
[   49.952195] last sysfs file: /sys/devices/pci0000:00/0000:00:01.1/host0/target0:0:0/0:0:0:0/block/sda/uevent
[   49.952195] CPU 1
[   49.952195] Modules linked in: pcspkr
[   49.952195] Pid: 3064, comm: dd Not tainted 2.6.30-rc3 #1
[   49.952195] RIP: 0010:[<ffffffff802d39a9>]  [<ffffffff802d39a9>] get_dirty_limits+0xe9/0x2c0
[   49.952195] RSP: 0018:ffff88001de03a98  EFLAGS: 00010202
[   49.952195] RAX: 00000000000000c0 RBX: ffff88001de03b80 RCX: 28f5c28f5c28f5c3
[   49.952195] RDX: 0000000000000000 RSI: 00000000000000c0 RDI: 0000000000000000
[   49.952195] RBP: ffff88001de03ae8 R08: 0000000000000000 R09: 0000000000000000
[   49.952195] R10: ffff88001ddda9a0 R11: 0000000000000001 R12: 0000000000000001
[   49.952195] R13: ffff88001fbc8218 R14: ffff88001de03b70 R15: ffff88001de03b78
[   49.952195] FS:  00007fe9a435b6f0(0000) GS:ffff8800025d9000(0000) knlGS:0000000000000000
[   49.952195] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   49.952195] CR2: 00007fe9a39ab000 CR3: 000000001de38000 CR4: 00000000000006e0
[   49.952195] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   49.952195] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   49.952195] Process dd (pid: 3064, threadinfo ffff88001de02000, task ffff88001ddda250)
[   49.952195] Stack:
[   49.952195]  ffff88001fa0de00 ffff88001f2dbd70 ffff88001f9fe800 000080b900000000
[   49.952195]  00000000000000c0 ffff8800027a6100 0000000000000400 ffff88001fbc8218
[   49.952195]  0000000000000000 0000000000000600 ffff88001de03bb8 ffffffff802d3ed7
[   49.952195] Call Trace:
[   49.952195]  [<ffffffff802d3ed7>] balance_dirty_pages_ratelimited_nr+0x1d7/0x3f0
[   49.952195]  [<ffffffff80368f8e>] ? ext3_writeback_write_end+0x9e/0x120
[   49.952195]  [<ffffffff802cc7df>] generic_file_buffered_write+0x12f/0x330
[   49.952195]  [<ffffffff802cce8d>] __generic_file_aio_write_nolock+0x26d/0x460
[   49.952195]  [<ffffffff802cda32>] ? generic_file_aio_write+0x52/0xd0
[   49.952195]  [<ffffffff802cda49>] generic_file_aio_write+0x69/0xd0
[   49.952195]  [<ffffffff80365fa6>] ext3_file_write+0x26/0xc0
[   49.952195]  [<ffffffff803034d1>] do_sync_write+0xf1/0x140
[   49.952195]  [<ffffffff80290d1a>] ? get_lock_stats+0x2a/0x60
[   49.952195]  [<ffffffff80280730>] ? autoremove_wake_function+0x0/0x40
[   49.952195]  [<ffffffff8030411b>] vfs_write+0xcb/0x190
[   49.952195]  [<ffffffff803042d0>] sys_write+0x50/0x90
[   49.952195]  [<ffffffff8022ff6b>] system_call_fastpath+0x16/0x1b
[   49.952195] Code: 00 00 00 2b 05 09 1c 17 01 48 89 c6 49 0f af f4 48 c1 ee 02 48 89 f0 48 f7 e1 48 89 d6 31 d2 48 c1 ee 02 48 0f af 75 d0 48 89 f0 <48> f7 f7 41 8b 95 ac 01 00 00 48 89 c7 49 0f af d4 48 c1 ea 02
[   49.952195] RIP  [<ffffffff802d39a9>] get_dirty_limits+0xe9/0x2c0
[   49.952195]  RSP <ffff88001de03a98>
[   50.096523] ---[ end trace 008d7aa02f244d7b ]---
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9e4a5bda
    • R
      kernel-doc: restrict syntax for private: and public: · 52dc5aec
      由 Randy Dunlap 提交于 
      scripts/kernel-doc can (incorrectly) delete struct members that are
surrounded by /* ...  */ <struct members> /* ...  */ if there is a /*
private: */ comment in there somewhere also.

Fix that by making the "/* private:" only allow whitespace between /* and
"private:", not anything/everything in the world.

This fixes some erroneous kernel-doc warnings that popped up while
processing include/linux/usb/composite.h.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      52dc5aec
    • N
      mm: close page_mkwrite races · b827e496
      由 Nick Piggin 提交于 
      Change page_mkwrite to allow implementations to return with the page
locked, and also change it's callers (in page fault paths) to hold the
lock until the page is marked dirty.  This allows the filesystem to have
full control of page dirtying events coming from the VM.

Rather than simply hold the page locked over the page_mkwrite call, we
call page_mkwrite with the page unlocked and allow callers to return with
it locked, so filesystems can avoid LOR conditions with page lock.

The problem with the current scheme is this: a filesystem that wants to
associate some metadata with a page as long as the page is dirty, will
perform this manipulation in its ->page_mkwrite.  It currently then must
return with the page unlocked and may not hold any other locks (according
to existing page_mkwrite convention).

In this window, the VM could write out the page, clearing page-dirty.  The
filesystem has no good way to detect that a dirty pte is about to be
attached, so it will happily write out the page, at which point, the
filesystem may manipulate the metadata to reflect that the page is no
longer dirty.

It is not always possible to perform the required metadata manipulation in
->set_page_dirty, because that function cannot block or fail.  The
filesystem may need to allocate some data structure, for example.

And the VM cannot mark the pte dirty before page_mkwrite, because
page_mkwrite is allowed to fail, so we must not allow any window where the
page could be written to if page_mkwrite does fail.

This solution of holding the page locked over the 3 critical operations
(page_mkwrite, setting the pte dirty, and finally setting the page dirty)
closes out races nicely, preventing page cleaning for writeout being
initiated in that window.  This provides the filesystem with a strong
synchronisation against the VM here.

- Sage needs this race closed for ceph filesystem.
- Trond for NFS (http://bugzilla.kernel.org/show_bug.cgi?id=12913).
- I need it for fsblock.
- I suspect other filesystems may need it too (eg. btrfs).
- I have converted buffer.c to the new locking. Even simple block allocation
  under dirty pages might be susceptible to i_size changing under partial page
  at the end of file (we also have a buffer.c-side problem here, but it cannot
  be fixed properly without this patch).
- Other filesystems (eg. NFS, maybe btrfs) will need to change their
  page_mkwrite functions themselves.

[ This also moves page_mkwrite another step closer to fault, which should
  eventually allow page_mkwrite to be moved into ->fault, and thus avoiding a
  filesystem calldown and page lock/unlock cycle in __do_fault. ]

[akpm@linux-foundation.org: fix derefs of NULL ->mapping]
Cc: Sage Weil <sage@newdream.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b827e496
  25. 01 5月, 2009 2 次提交
  27. 29 4月, 2009 1 次提交
  29. 28 4月, 2009 1 次提交
  31. 27 4月, 2009 4 次提交
  33. 25 4月, 2009 1 次提交
  35. 23 4月, 2009 3 次提交
  37. 22 4月, 2009 1 次提交
  39. 21 4月, 2009 2 次提交
  41. 19 4月, 2009 2 次提交